Zero Modes for the D=11 Membrane and Five-Brane

There exist extremal p-brane solutions of $D\!=\!11$ supergravity for p=2~and~5. In this paper we investigate the zero modes of the membrane and the five-brane solutions as a first step toward understanding the full quantum theory of these objects. It is found that both solutions possess the correct number of normalizable zero modes dictated by supersymmetry.Comment: Minor typos corrected, one reference added, agrees with published version. 9 RevTeX pages, 1 figure include

Charged Particles and the Electro-Magnetic Field in Non-Inertial Frames of Minkowski Spacetime: I. Admissible 3+1 Splittings of Minkowski Spacetime and the Non-Inertial Rest Frames

By using the 3+1 point of view and parametrized Minkowski theories we develop the theory of {\it non-inertial} frames in Minkowski space-time. The transition from a non-inertial frame to another one is a gauge transformation connecting the respective notions of instantaneous 3-space (clock synchronization convention) and of the 3-coordinates inside them. As a particular case we get the extension of the inertial rest-frame instant form of dynamics to the non-inertial rest-frame one. We show that every isolated system can be described as an external decoupled non-covariant canonical center of mass (described by frozen Jacobi data) carrying a pole-dipole structure: the invariant mass and an effective spin. Moreover we identify the constraints eliminating the internal 3-center of mass inside the instantaneous 3-spaces. In the case of the isolated system of positive-energy scalar particles with Grassmann-valued electric charges plus the electro-magnetic field we obtain both Maxwell equations and their Hamiltonian description in non-inertial frames. Then by means of a non-covariant decomposition we define the non-inertial radiation gauge and we find the form of the non-covariant Coulomb potential. We identify the coordinate-dependent relativistic inertial potentials and we show that they have the correct Newtonian limit. In the second paper we will study properties of Maxwell equations in non-inertial frames like the wrap-up effect and the Faraday rotation in astrophysics. Also the 3+1 description without coordinate-singularities of the rotating disk and the Sagnac effect will be given, with added comments on pulsar magnetosphere and on a relativistic extension of the Earth-fixed coordinate system.Comment: This paper and the second one are an adaptation of arXiv 0812.3057 for publication on Int.J.Geom. Methods in Modern Phys. 77

Twenty Years of the Weyl Anomaly

In 1973 two Salam prot\'{e}g\'{e}s (Derek Capper and the author) discovered that the conformal invariance under Weyl rescalings of the metric tensor $g_{\mu\nu}(x)\rightarrow\Omega^2(x)g_{\mu\nu}(x)$ displayed by classical massless field systems in interaction with gravity no longer survives in the quantum theory. Since then these Weyl anomalies have found a variety of applications in black hole physics, cosmology, string theory and statistical mechanics. We give a nostalgic review. (Talk given at the {\it Salamfest}, ICTP, Trieste, March 1993.)Comment: 43 page

Exact Absorption Probability in the Extremal Six-Dimensional Dyonic String Background

We show that the minimally coupled massless scalar wave equation in the background of an six-dimensional extremal dyonic string (or D1-D5 brane intersection) is exactly solvable, in terms of Mathieu functions. Using this fact, we calculate absorption probabilities for these scalar waves, and present the explicit results for the first few low energy corrections to the leading-order expressions. For a specific tuning of the dyonic charges one can reach a domain where the low energy absorption probability goes to zero with inverse powers of the logarithm of the energy. This is a dividing domain between the regime where the low energy absorption probability approaches zero with positive powers of energy and the regime where the probability is an oscillatory function of the logarithm of the energy. By the conjectured AdS/CFT correspondence, these results shed novel light on the strongly coupled two-dimensional field theory away from its infrared conformally invariant fixed point (the strongly coupled ``non-critical'' string).Comment: Latex (3 times), 23 page

Disability and the Income Tax

The federal Income Tax Act contains an extensive number of provisions addressing the taxation of families with disabled persons. These provisions, however, have been the subject of a series of ongoing incremental adjustments, and do not reflect a comprehensive and coherent approach to the taxation of these individuals in light of their unique financial circumstances. This article considers the existing income tax provisions regarding families with disabled persons, analyzing the relationship between disabilities and appropriate tax liabilities, and providing suggestions for reform of the current tax structure. Focussing on the goals of tax policy narrowly defined as compared to the broader social policy goals that may be pursued through the tax system, the article evaluates in turn (i) existing provisions aimed at recognizing the costs of disability for disabled individuals and their families; (ii) tax measures designed to facilitate participation by disabled persons in the paid labour force; and (iii) current tax rules on income support for disabled persons who have difficulty supporting themselves. In each of these areas, the article undertakes critical analysis of the present tax provisions and makes proposals for their improvement or replacement, bearing in mind the overriding rationale of promoting horizontal equity between individuals with and without disabilities and between persons who support disabled individuals and persons without such support obligations

Recognizing or Disregarding Close Personal Relationships Among Adults? The Report of the Law Commission of Canada and the Federal Income Tax

Beyond Conjugality, the Report of the Law Commission of Canada on close personal relationships among adults, reviews a number of federal statutes in which legal consequences turn on specific kinds of relationships among adults, and it proposes a new methodology for assessing existing or proposed legal rules that employ relational terms in order to accomplish their objectives. This comment on the Report addresses its most significant recommendations regarding personal income taxation and income support in Canada: that the tax credit for spouses and common law partners should be repealed and that the GST credit should be fully individualized. Questioning both of these recommendations, the comment draws some general conclusions on the Report\u27s vision of close personal relationships among adults, at least as these affect issues of income taxation and support

Tax Treaty Abuse and the Principal Purpose Test: Part II

The Multilateral Convention to Implement Tax Treaty Measures to Prevent Base Erosion and Profit Shifting or Multilateral Instrument (MLI) has been described as “an historical turning point in the area of international taxation” which introduces a third layer of tax rules for the taxation of cross-border transactions in addition to domestic tax law and bilateral tax treaties. Of the many provisions of the MLI, the most important are the preamble text in Article 6(1) and the so-called principal purpose test (PPT) in Article 7(1), both of which have been adopted by all signatories to the MLI in order to satisfy the OECD’s minimum standard on tax treaty abuse under BEPS Action 6. This two-part article considers the structure and potential application of the PPT in the context of pre-BEPS responses to perceived tax treaty abuses, the OECD’s work on BEPS Action 6, and other provisions of the MLI including the preamble text in Article 6(1). The first part, in the previous issue of the Journal, reviewed pre-BEPS responses to perceived tax treaty abuses, providing necessary background and context for understanding BEPS Action 6, the MLI and the PPT. The second part, in this issue of the Journal, examines the PPT in light of this background and in the context of BEPS Action 6 and other provisions of the MLI, considering its relationship to other anti-avoidance doctrines, principles and rules, the various elements that comprise its basic structure, the kinds of transactions or arrangements to which it may be expected to apply, and the consequences of its application

Tax Treatment of Charitable Contributions in a Personal Income Tax: Lessons from Theory and Canadian Experience

A hundred years after tax concessions for charitable contributions were introduced as part of the personal income taxes that many countries enacted during the First World War, these countries continue to debate the appropriate level and structure of tax concessions for charitable gifts. This chapter considers the tax treatment of charitable contributions in a personal income tax, reviewing and evaluating alternative rationales for tax recognition of charitable gifts as well as the implications of these rationales for the form that tax recognition should take, and examining recent Canadian experience in light of these rationales

Canadian Bijuralism and the Concept of an Acquisition of Property in the Federal Income Tax Act

The acquisition of property plays an important role in the federal Income Tax Act (ITA), determining eligibility for a number of tax benefits, including entitlement to capital cost allowance, investment tax credits, and the deductibility of interest expenses incurred in respect of eligible property. In spite of its importance, the concept of an acquisition of property is not defined in the ITA, and it has been subject to divergent interpretations in the common law and the civil law. The author traces the sources of law informing the meaning of an acquisition of property in the common law and the civil law, and concludes that certain transactions may be subject to different tax consequences depending on whether they occurred in a common law province or in Quebec. The author demonstrates that the primary reference for determining whether a taxpayer acquired property — the twofold test in M.N.R. v. Wardean Drilling Ltd. — is premised on common law concepts and is incompatible with the goals of Canadian bijuralism expressed in the Federal Law — Civil Law Harmonization Act, No. 1 and section 8.1 of the federal Interpretation Act. In response to this contradiction, the author proposes a number of statutory amendments to ensure the uniform and predictable application of the ITA across Canada